Enciphering apparatus



March 3- G. GARINIER 2,313,012

ENCIPHERING APPARATUS Filed Dec. 27, 1938 3 Sheets-Sheet l Mrch2,1943.G. GARNIER 2,313,012

ENCIPHERING APPARATUS Filed Dec. 27, L938 s Sheets-Sheet 2 March G.ARNlER ,31

ENGI PHERING APPARATUS Filed Dec. 27, 1958 s Sheets-Sheet 3 PatentedMar. 2, 1943 -r ENCIPHERING APPARATUS Gustave Garnier, Paris, France;vested in the Alien Property Custodian Application December 27, 1938,Serial No. 247,957 In France January 6, 1938 1 Claim.

The present invention has for object a very simple apparatus allowing tovery easily and rapidly translate plain-texts into cipher and,reversely, cryptograms into plain-texts, and this with a number ofavailable combinations so considerable that it is practically impossiblefor a non-authorized person to decipher them.

This apparatus essentially comprises a disc which is movable about itscentre underneath a fixed plate or dial perforated with radialapertures. The letters of the alphabet are inscribed on the edges ofsaid apertures'in such an order that it is easy to rapidly find each ofthem.

On the other hand, the movable disc bears on its entire annular zonecapable of appearing at the apertures of the fixed dial, cryptographiccharacters or signs adapted to be substituted for the letters inscribedon the edge of said apertures, the number of said characters or signsbeing a multiple of that of the letters of the alphabet, and theirpositions in said zone being suitably chosen, so that for each positionof the disc the characters appearing in the apertures opposite theletters of the alphabet are all different from each other.

Said movable disc is preferably composed of two or more elements whicheach bear a certain number of the cryptographic characters and therelative positions of which can be changed at will, so that the orderaccording to which all said characters pass in one and the same apertureis Variable in view of multiplying the num ber of availablecombinations.

The accompanying drawings diagrammatically illustrate and by way ofexample only, a form of construction of the subject-matter of theinvention.

Fig. 1 is a vertical section passing through the centre of theapparatus.

Fig. 2 is a top plan view. I

Figs. 3 and 4 illustrate separately the two elements of themovable'disc.

Fig. 5 is a section of a modification, made according to line I-I ofFig. 6.

Fig. 6 is a top plan view of this apparatus.

Fig. 7 is a plan view of the movable disc composed of four superposeddiscs, the three upper discs being partly broken away.

Fig. 8 shows the numbered crown, or ring.

Only a small number of the cryptographic characters have beenillustrated in these figures so as not to unnecessarily complicate thedraw ings.

II I designates a dial supported'at a short distance above a base H2,for instance by means of supports H3 or of a circular fiangaetc. Betweenthis plate and the base is placed the movable disc pivoting about a pinHA. In this example the disc is composed of two superposed elements: alower disc H5 and an upper disc I I6, which are secured to each other byany attaching means Ill allowing to change at will their relativeangular position.

The dial HI is perforated with a certain number of radial apertures I I8on one edge of which. are inscribed the letters of the alphabet, that isto say for instance the twenty-six letters of the English alphabet intheir natural order from left to right along the successive apertures;in. the drawings, five apertures have been illustrated each bearing fiveletters and a smaller aperture:

bearing the twenty-sixth letter (Z). The an gular widths of theseapertures and those of the solid portions separating them aresubstantially equal to an amount which will be called angular: pitch.

Concentrically with the row of apertures, a slot H9 in the shape of anarc of circle is provided. in the dial Ill, and the figures 0 to 9 or 0to 10 are inscribed on one edge of said slot at intervals or angularpitches which are equal to the width of the apertures H8.

On the movable discs H5 and H6 the cryptographic characters areinscribed on the entire annular zone which, by rotating, passes underthe apertures H8; these characters are arranged according to radial rowsthe spacing apart of which corresponds to the angular pitch previouslymentioned, and according to concentric circumferences corresponding tothe radial spacing apart of the letters of the alphabet along theapertures. It results therefrom that for each position of the doubledisc H5, H6, twenty-six cryptographic characters appear opposite thetwenty-six letters of the alphabet and express the respectivetranslations for this position.

In the example illustrated, the angular pitch is equalto %2 ofcircumference, and the disc bears 5X52=260 characters, that is to saythe value of ten alphabets.

Each character is repeated thereon ten times, that is to say five timeson disc H5 and five times on disc H6. 7

Figs. 3 and 4 show that the upper disc H6 is cut out on its periphery soas to have twenty-six teeth and twenty-six notches, each of said teethbearing five characters and each notch allowing five charactersinscribed on th disc H5 to be seen.

Attaching means H! are provided so that each tooth of disc I [6 can bemoved and held stationary between any two radial rows of characters ofdisc H; the setting of one disc relatively to the other is easy owing tothe numbering of the rows of characters on said two discs.

One of the apertures H8 is extended up to above the ring of numbers ofdisc H5 and allows of marking out the position of the latter relativelyto the dial l l I.

For causing the double disc H5, H6 to rotate, use can be made of apencil or of any stylus the point of which is engaged in the slot H9 andin one of the fifty-two holes l2!) provided in the periphery of disc H5.7

It it is desired to rotate the double disc 12 number of steps, smalleror equal to 10, in the direction of the arrow F, the point is engaged inthe hole I located opposite the number n inscribed on the edge of theslot H9 and said point is brought up to the end of the slot marked 0.

Thus can be caused to appear in the apertures H8, every time the movabledisc is thus rotated, according to code agreedupon, one of the fiftytwocombinations of twenty-six characters corresponding to the fifty-twopossible positions of the disc.

As these combinations of twenty-six characters can be changed bydisplacing the disc I 66 on disc H5; the operator has, in reality, athis disposal 52 2B=1352 cryptographic alphabets for translating theplain alphabet, This number is quadrupled if each elementary disc bearscharacters on both its faces.

On the other hand, the movable disc can itself be replaced by othersimilar discs but the characters of which are inscribed in different.orders, so that the number of cryptographic alphabets at the disposal ofthe operator is practically illimited.

The graduated slot H9 is particularly adapted to increase in aconsiderable proportion the num.- ber of changes of combinationsutilisable during the translation of one and the same text.

For instance, the various elements of disc H 5e! l6 can be designatedaccording to the successive figures of a number agreed upon beforehand,which can be as long as desired (the decimals of the number 1r amongstothers).

The successivedesignation of the elements. of the disc can also be basedon a countersign agreed upon; for instance with the word Vendome, V.will be'designated by 22 steps of the rotating disc, E'by 5 steps and Nby 14 steps etc.

These two methods of designation are indicated only among an infinitenumber of others the choicev of which can always be modified asthecorrespondents desire.

The direction of rotation of the disc can itself be conventionallychanged, for instance that of. the arrow F on odd days, the reversedirectionon even days, etc. 7

It is to be noted that the. distribution of; the characters on eachdisc, whether the latter is double as illustrated, or triple, orquadruple, etc. or simple, must always be established in sucha mannerthat all the combinations of twenty-six characters which the disc iscapable of presenting under the apertures H8 are differentv from eachother, and that each of them never comprises a repetition of one and thesame character, which repetition might prevent the easy deciphering of asecret text.

In th example illustrated, the disc .is dividedinto fifty-two sectors orsteps, but it is to. beunderstood thatit can, in a. general manner, be

divided into n A steps, A being the number of the letters of thealphabet (English or other alphabet) and it any whole number whatever.

In the example illustrated the letters are arranged according to fiveconcentric crowns or rings, but it is to be understood that, withoutdeparting from the scopeof the invention, the number of said concentriccrowns or rings can be varied, the angular pitch of the divisions beingindependent of this number and remaining equal to 360 /nA.

For facilitating the changing of the discs, the dial can be hingedlymounted on its supports in any suitable and removable manner, and thediscs can be simply threaded on the pivot H4.

In Figs. 5 to 8, a designates a base at the centre of which is secured avertical pin b serving as a pivot for the movable disc 0; above thelatter a fixed dial or cover (1 is secured by a nut e on the pin b andheld stationary by tenons f freely engaged in holes formed in said dial.

In this example, the movable disc is composed of a rigid disc 01 servingas support, of four cryptographic discs 02 c3 c4 c5 of small thickness,for instance made of brass, and of a rigid crown or ring cs; theseelements are freely superposed and their relative positions aremaintained by means of teno-ns g secured to the disc 01 and freelyengaged in holes it formed in the discs 02 to 05 and in the crown orring cs.

Each of the thin discs is divided into 104 elementary sectors; on thelower disc 02 (Fig. 7) are inscribed 104 groups of 7 letters, occupyingall the sectors; the disc ca'is perforated with 26 apertures i uniformlyspaced apart each having the width of an elementary sector, and bearsgroups of 7 letters inscribed either on one edge only of each aperture,or on both edges, or moreover, in the intermediary sectors; the disc 04is also perforated with 26 apertures 7', but the latter each have thewidth of '2 elementary sectors, and groups of '7 letters. are inscribedon one edge or on both edges of each'aperture; the disc 05 is perforatedwith 26 apertures is having a width of three elementary sectors andbears a group of 7 letters on each of the sectors separating theapertures.

Finally, in the fixed dial. dYFig- 6) are cut out apertures m and 11,eachof which has a width of one elementary sector and is separated fromthe next one by a solid portion having. a triple width. The edges ofthese apertures are'bevelled in order to facilitate the reading of thecryptographic discs.

The four apertures m, adapted to translate texts, have a total lengthallowing to read at the same time 26 letters on the movable disc and, inaddition, one of. the 104 numbers carried by the crown or ring asopposite its EM reference holes h.

The twoaperturesn, provided for the translation of figures andconventionalsigns, have a total length allowing to read on the movabledisc a number of lettersequalto the number of these figuresand signs,for instance 12..

Theletters, figures and signsto be translated are engraved on one edgeof these different apertures, in their normal order.

In the crown or ring caareperforated, in addition, tothe holes h, 104holes. p, equally spaced apart on a. larger circumference,v and servingto operatev the movable disc by means of a point or stylus which theoperator moves through a slot q inlthe shape of'an arc of circleprovidedin the diald. and having. a. length equal,'. for instance,

to about 10 elementary sectors. Owing to a graduation numbered on theedge of said slot the movable disc can thus be rotated to the extent ofone or more divisions, either in one direction or in the other at will.

It is to be remembered that the choice of the letters inscribed on thediscs c2 c3 c4 05 must be such that, whatever may be the positions ofsaid discs relatively to each other and to the fixed dial, the letterssimultaneously appearing in the apertures m are different from eachother; the same will then be true for those simultaneously appearing inthe apertures n.

I claim:

An enciphering apparatus comprising the combination of a base, a platepivotally mounted on said base and having registering projections on itsupper face, a plurality of discs superposed on said plate and eachhaving a circular series of apertures adapted to engage over saidprojections, said discs being provided with a series of uniformly spacedradial slots and bearing a plurality of indicia on one edge of each ofsaid slots, said apertures being provided in a number which is amultiple of the number of said slots, a ring-shaped disc placed abovethe periphery of said discs and having two concentric series ofapertures the spacing apart of which corresponds to that of theapertures of said discs, the apertures of the inner series being adaptedto engage over said projections, and a non pivoting cover having aplurality of radial slots and bearing on one edge of each of said slotsa plurality of letters of the normal alphabet, said cover also having aslot made according to an are extending above the outer series ofapertures of said ring-shaped disc.

GUSTAVE GARNIER.

